THE METHOD OF ORGANIC EVOLUTION. 425 



to overcome, and how tliey are the beginnings of the establishment of 

 a sure base for the attack on the problems of evolution. In so doing- 

 he has entirely failed to grasp the essential features which characterize 

 at least 99 per cent of existing species, which are, slight differences 

 from their allies in size, form, proportions, or color of the various i^arts 

 or organs, with corresponding differences of function and habits, com- 

 bined with a wonderful amount of stability in the numerical relations 

 of serial parts, extending sometimes only to genera, but more usually 

 to families, tribes, orders, or even to whole classes of the higher ani- 

 mals. It is differences of the former kind that do actually characterize 

 the great majority of species;' they affect those organs which varj^ 

 most frequently and most conspicuously in the individuals of every 

 fresh generation, and they constitute that individual variation on 

 which Darwin always relied as the essential fouiulation of natural 

 selection, and which his followers have shown to be fiir more abundant 

 and of far greater amount than he was aware of; and, lastly, they 

 afford amply sufficient material for the continuous production of new 

 forms. Earely in the history of scientific progress has so large a claim 

 been made, and been presented to the world with so much confidence 

 in its being an epoch-making discovery, as Mr. Bateson's idea of dis- 

 continuous variation corres[)onding to and explaining the discontinuity 

 of species; yet more rarely has the alleged discovery been supported 

 by facts which, though interesting in themselves, are for the most part 

 quite outside the general conditions of the complex problem to be 

 solved, and are therefore entirely worthless as an aid to its solution. 



Before leaving this part of the subject we may note the extension of 

 definite numerical relations to plants as well as to animals. In dico- 

 tyledons we have a typical five-petaled flower, or a corolla with five 

 divisions, a character which prevails in irregular as well as in regular 

 flowers, and often when the stamens are not a multiple of five, as in 

 mallows, bignonias, and many others. Some form of fi\ e-parted flower 

 l^revails throughout many extensive natural orders, and comprises prob- 

 ably a considerable majority of all dicotyledonous plants. A three or 

 six parted flower is almost equally a characteristic of monocotyledons, 

 prevailing even among the highly specialized and firntastically formed 

 Orchidea' and Iridea^, thus again demonstrating how large a portion of 

 the si)ecific modifications of organisms are independent of variations 

 ill number, but depend wholly upon variations in the size, form, color, 

 and structure of the various parts and organs. 



Other matters of importance in Mr. Bateson's work, together with 

 some theories recently advanced by Mr. Francis Galton," will be dis- 

 cussed in the concluding portion of this article. 



'Mr. Batesoii", however, makes the extraordinary statement that "it is especially 

 by differences of number and bj'^ qnalitativo differences that species are commonly 

 distinguished" (p. 573). Species makers know too well that, among the higher 

 animals at all events, it is not so. 



